Low temperature polysilicon (LTPS) technology is a new generation of Thin Film Transistor (TFT) substrate manufacturing technology. Compared with conventional amorphous silicon (a-Si) technology, LTPS display device has advantages of high response speed, high brightness, high resolution, and low power consumption. Polysilicon (Poly-Si) has excellent electrical properties and has a good drive capability as to the active matrix organic light-emitting diodes (AMOLED). As a result, AMOLED display backplates based on LTPS polysilicon technology are widely used at present.
AMOLED display backplate manufacturing methods based on mere LTPS technology or oxide technology are methods currently used widely, and the AMOLED display backplate manufactured through the two technologies have good electrical properties and can have a very good drive capability. In addition, polysilicon prepared through Solid Phase Crystallization (SPC) method has good uniformity, low electric leakage, and better stability, and thus the SPC method has become a good method for manufacturing AMOLED backplate.
At present, LTPS is prepared through Excimer Laser Annealing (ELA) technology. According to ELA technology, instantaneous pulse of a laser irradiates on the surface of the amorphous silicon, so that the amorphous silicon can be melted and recrystallized. However, according to ELA crystallization technology, lattice uniformity and crystal orientation cannot be controlled effectively, and thus polysilicon cannot be formed on the whole substrate in a uniform manner. As a result, an image displayed by a display device manufactured thereby is non-uniform, and mura would appear. In addition, the display device would have a high electric leakage.